--Who is the boy over there?Is it john?

问题描述:

--Who is the boy over there?Is it john?
--No,it_____ be him.John is much taller.
A.mustn't
B.may not
C.can,t
D.needn't
--John ______ come to see us tonight,but he isn't very sure yet.
A.may
B.can
C.has to
D.must
两问,选啥?为啥?

C,can't be 表推测
A,may表不确定,后面有not sure嘛